The present invention is a process for reacting organic halides with disilanes to form monosilanes. The process uses disubstituted palladium compounds as catalysts. The process is especially useful for reacting alkenyl chlorides, such as allyl chloride, with disilanes to form monosilanes having alkenyl substitution. The process is also useful for converting the high-boiling disilane containing fraction resulting from the direct process for forming organosilanes into more useful monosilanes.
The primary commercial method for producing organosilanes involves the reaction of an organic halide with elemental silicon. After the desired organosilanes have been recovered from the product mixture by distillation there remains a high-boiling residue which comprises among other components disilanes. Since these disilanes have very little commercial value it is desirable to convert them to the more useful monosilanes. The present invention relates to a process for converting disilanes to monosilanes by contacting the disilanes with and organic halide in the presence of a disubstituted palladium catalyst. In the process the Si--Si bond of the disilane is broken resulting in the formation of two monosilanes, with the organic group of the organic halide substituting on one of the silicon atoms and the halogen group of the organic halide substituting on the other silicon atom.
Atwell et al., U.S. Pat. No. 3,772,347, describe the use of palladium/phosphine compounds as catalysts for the reaction of disilanes and organic halides to form monosilanes. Atwell et al. teach such catalyst are useful, for example, for the reaction of hexachlorodisilane with allyl chloride to give allyltrichlorosilane.
Eaborn et al., J. Organometallic Chem. 225:331-341 (1982) describe the reactions of a range of organic halides with hexamethyldisilane or hexachlorodisilane in toluene in the presence of a palladium catalyst containing phosphine ligands.